The present invention is adapted to provide a replacement for conventional apparatus used to discharge exhaust air from a building. Such apparatus commonly includes a housing adapted to be mounted on a roof of a building and may include a fan for discharging air from the building.
Most prior art ventilation systems place additional burdens on the heating, ventilating and air conditioning systems of a building. Expensively conditioned air is exhausted along with contaminants while make-up air must be brought in and conditioned in order to provide safety and comfort. Shortcuts such as reduced exhaust or reduction of make-up volumes create problems and discomfort for the occupants of the building.
Contaminants in the air must be removed efficiently in order to provide safety and comfort for building occupants, and local codes must be followed to insure the proper air changes are provided. Exhausted air must be replaced by fresh, uncontaminated air to provide a healthy environment in the building and the make-up air must be provided in sufficient quantity so as to produce a positive pressure in the building in order to prevent the expense and discomfort of drafts and infiltration.